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O. E. SGRIBNE'R.

TEST SYSTEM FOR MULTIPLE SWITGH BOARDS.

No. 385,205. Patented June 26,1888

U m M L S FL. I- ,Q Z w S G W? I I. SSS

(NO Model.)

CHARLES E. SCRIBNER, OF CHICAGO, ILLINOIS, ASSIG-NOR TO THE WESTERN b ELECTRIC COMPANY, OF SAME PLACE.

TEST SYSTEM FOR MULTIPLE $VVITCH-BOARDS.

SPECIFICATION forming part of Letters Patent No. 385,205, dated June 26,, 1888.

Application filed December 27, 1886. Renewed November 21, 1587. Serial No.255,771. (No-model.)

T aZZ whom, it may concern: liue is closed to the subscribers station. If, Be it known that I, CHARLES E. SORIBNER, however, there is a break in the line between a citizen of the United States, residing at Chithe spring-jack that is being tested and the eago, in the county of Cook and State of Illisubscribers station, the circuit of the battery nois, have invented a certain new and useful and electro-magnet of the testing apparatus 5 Improvement in Test Systems for Multiple will remain open and the armature will fall Switch-Boards, (Case 124,) of which the folback to its normal position.

lowing is a full, clear, concise, and exact de- My invention may be readilyunderstood by scription, reference being had to the accomreference to the accon'ipanying drawings, in

re panying drawings, formingapart of this speciwhich 60 fication. Figure 1 shows two telephonelines, each In multipleswitchboard systems, in order connected through a different spring-jack on to avoid confusion, it is necessary to test each each of three multiple switch-boards, and from line called for before making the connection the switches on the last heard through polarbetween the line of the subscriber calling and ized anuunciators to ground. Fig. 2 is a de- 6 the called subscribers line. Many different tailed view of the polarized annuuciator and systems of testing have been heretofore dcthe groundcontact for shunting the said anvised for doing this work. One of the sysnuneiator out of circuit.

B terns is shown in mypatent for improvement Atthe first and third boards I have shown in multiple switch-board systems, No. 321,390, the usual keyboard apparatus, and at the secof June 30, 1885. By the use of my invention cud board I have shown the testing apparatus herein I am enabled to dispense with the test which I have invented. keys and the test portion of the line with said The circuit of line a may be traced through test-keys on the different boards described and the springjack switches on boards 1 2 3, and

25 claimed in said patent. through polarized annunciator Z) to ground.

Myinvention eonsistsin providing a polar- Circuit of line 0 may be traced in like manner ized annuuciator of high resistance in the cirthrough a spring-jack on each of the boards cuit of each line after it has passed through its and through polarized annunciator d to spring jacks, and means for momentarily ground.

39 shunting any one of these polarized annunci- As shown in Fig. 2, the armature of the ators out of circuit when the test is made at polarized annunciator is connected with a flat. the line. The testing apparatus used at each spring, and when current is sent from the sub board consists of an electro-magnet provided scribers generator in reversals the armature with two wiudingsone of, say, half an ohm of the polarized annuneiator will vibrate and 3 5 resistance, and the other winding of, say, one allow the shutter to fall. When, however, 8 5 hundred ohms resistance-a battery of modercurrent is sent from any tcst'battery through ate size-say three or four cells included in any polarized annunciator, the annunciator is the circuit of said electro-maguet and switchso set that its armature will be simply moved ing apparatus, whereby on connecting the cirdownagainst the ground contact-point, thus 0 unit of the electro-magnet to a line that is not shunting out the coils of the said polarized anin use the armature of the electro-magnet of nunciator without throwing down the shutter. the testing apparatus will be moved to break The testing apparatus may consist of the the shunt around the high-resistance winding plug 6, the cord f, connected therewith, the of said electro-magnet when the polarized anelectro-magnet provided with low-resistance 5 nunciator of the line is momentarily shunted winding 9 and high-resistance winding h, the 5 out of circuit. Both windings of the electroarmature i of said electroinaguet, connections magnet of the testing apparatus being thusinis Z, and the test-battery m. I preferably pro- 4 cluded in the circuit, its armature willbe held vide, also, a vibrating bell, n, in a local cirin position to maintain the circuit through cuit, as shown. The winding 9 is of suchlow 50 the high-resistance winding to the line if said resistance that current from battery m, when at board 2 wishes to make a test to determine.

whether or not a connection has been made with the line either at board 1 or board 3. He makes this test by simply inserting test-plug 6 into the spring-jack, as shown. \Vhen thetip of plug 6 first touches the springof the jack, current from battery m is sent through annunciator b to ground, thus closing the armature of polarized annunciator b to ground-contact, and thus shunt-ing out the resistance of the coils of the electro-magnet of annunciator b. This shunt around annunciator b is closed as soon as the tip of pluge touches the spring of the spring-jack, and before said spring is wedged away from its normal contact-point. The resistance of annunciator 5 being this removed from the circuit, battery at will be closed momentarily through the low-resistance winding 9 directly to ground, and armature i will thus be separated from its normal contact is and closed to contact Z, as shown. The shunt around high-resistance windinghisthusopened at k and the local circuit through hell a at the same time closed at Z. Now, if the circuit of battery on is closed through winding 9 and winding h to plug 0, and thence to the spring of springjaek in which the plug 6 is inserted, and to line a through the spring-jack of this line on the first board, the armature t will still be attracted by the magnet and the local circuit will remain closed through bell n. Therefore, if bell n rings the operator knows that the line is free.

In case the line is broken at the board following the one at which the test is being made, no circuit will be closed in the first instance when the test-plug is inserted and the armature 'i will not be moved. On the other hand, if the line is open at the spring-jack of the line on board 1, as soon as the spring of the spring-jack in which the test-plug is inserted is wedged away from its normal contact the battery m will find no circuit to line, since the line will be dead open at the preceding board.

It will be noted that by the use of my testing apparatus I testin two directions-first to ground at the central office and then over the line to the subscribers station. I am thus enabled to determine whether the line is open on either side of the springjack at which the test is made. If the test indicates that the line is open on either side, the operator will know that the line is in use. If, however, he

finds that the line is closed in both d i-rections, he will know that the line is free. Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. A telephone-line connected with a switch through a polarized annunciator to ground, in combination with a shunt around said polarized annunciator,which is closed when current is sent in one direction through the annunciator, and testing apparatus consisting of an electro-magnet having two windings, one of low resistance and the other of high resistance,a battery included in a normally-open ground-circuit with said electromagnet, and switching apparatus whereby on closing said circuit to line at any switch of the line the shunt will be closed around the polarized annunciator, and thereupon the circuit of the testing apparatus is changed so as to include the high-resistance winding, substantially as described.

2. The, combination, with a telephone-line passing through a series of spring-jacks, the spring-jack switches being distributed on different boards, of a polarized annunciator included in said line between the switch on the last board and the ground, a shunting device operated by the armature of said polarized annunciator to shunt out the coils immediately on said annunciator-magnet being energized, a ground-circuit including a battery and a doubly-wound electro-magnet of a signal device, said windings being of high and low resistance, respectively, a circuit-closing device actuated by the armature of said relay to bring the fine-wire coil into circuit on closing the battery through the coarse-wire coil directly to ground, and a plug terminal adapted to be inserted in any one of the spring-jack switches of the line, whereby on inserting the plug in any switch the line may be tested in both directions, substantially as specified.

3. Atelephone-line passing through a series of spring-jack switches and through a polarized annunciator to ground,a shunt around said polarized annunciator, which is closed when current is sent in one direction through the annunciator, and testing apparatus consisling of a battery included in a ground-circuit with anelectro-magnet having two windings,one of low resistance and the other ofhigh resistance, and switching apparatus whereby on closing said circuit to any switch of the line the shunt will be closed around the polarized annunciator, and thereupon, the re sistance of the'coil of the polarized annunciator being removed from the circuit, the circuit of the testing apparatus will be changed to include the high-resistance winding, substantially as described.

4. The combination, with a telephone-line connected with a different spring-jack switch on different sections of a multiple switchboard,ot' a polarized annunciator and a shunting device connected by the armature thereof,

on each of two or more switch-boards and on inserting the plug farther to lift the spring of the switch at which the line is being tested in the other direction, substantially as described.

In witness whereof I hereunto subscribe my 15 name this 16th day of November, A. D. 1886.

CHARLES E. SORIBNER. \Vitnesse's:

GEORGE P. BARTON, WM. M. GILLER. 

